2.1. Sample preparation
A total of sixty-nine shrimp that showed clinical signs of CMNV infections including death shrimp, and shrimp of whitish muscle necrosis, abdominal muscle coloration, hepatopancreatic atrophy and necrosis were collected from shrimp farms in four southern provinces of Thailand. The samples were tested to verify that they had not been infected by other virus and bacteria including WSSV, IHHNV, TSV, YHV, infectious mionecrosis virus (IMNV) and Vibrio parahaemolyticus. Shrimp samples infected with other RNA viruses (i.e., TSV, YHV, or IMNV) were also utilized to determine the cross reaction of other RNA virus with CMNV.